1. Field of the Invention
The present invention generally relates to an IC card and, more particularly, to a combination card which can exchange data with an external device by both a contacting method and a non-contacting method.
Presently, in order to connect an IC card to an external device, there are two methods, one is a contacting method and the other is a non-contacting method. In the contacting method, an IC card having terminals exposed on a surface thereof is used. When such an IC card is attached to the external device, the terminals of the external device are made in contact with the terminals of the IC card and are electrically connected thereto so that data exchange can be performed between the IC card and the external device.
On the other hand, in the non-contacting method, an IC card provided with an antenna inside thereof is used. When such an IC card is attached to an IC card reader or positioned close to the IC card reader, data exchange is performed by radio communication between the IC card and the IC card reader. Relatively simple data is exchanged by the non-contacting method. For example, data used for an attestation of an ID number in a security system may be exchanged by the non-contacting method.
There is a combination card, which is an IC card that can be used by both the contacting method and the non-contacting method. That is, the combination card, is an IC card provided with both the connection terminals for exchanging data by the contacting method and an antenna for exchanging data by the non-contacting method.
2. Description of the Related Art
A description will now be given, with reference to FIGS. 1 to 6, of a conventional combination card. FIG. 1 is a plan view of a conventional combination card.
As shown in FIG. 1, the conventional combination card comprises a card body 1 and an IC card module 2 (hereinafter simply referred to as a module) incorporated in the card body 1. The card body 1 is made of a plastic material. A loop antenna 3 is incorporated in the card body 1.
A plurality of external connection terminals (electrodes) 4 are formed on one side of the module. The module 2 is incorporated in the card body 1 so that the external connection terminals 4 are exposed on the surface of the card body 1. Hereinafter, the surface on which the external connection terminals 4 are exposed is referred to as a terminal surface. When the combination card is used by the connecting method, the data exchange is performed by the external connection terminals 4 contacting the terminals of the external devices.
Antenna terminals 5 are provided on a side of the module 2 opposite to the terminal surface. Opposite ends of the antenna 3 are connected to the antenna connection terminals 5. Hereinafter, the surface opposite to the terminal surface of the module 2 is referred to as a mounting surface.
A description will now be given, with reference to FIGS. 2 to 4, of a structure of the module 2. FIG. 2 is a plan view of the terminal surface of the module 2. FIG. 3 is a plan view of the mounting surface of the module 2.
The module 2 comprises a circuit substrate 7 and an IC chip 8 (refer to FIG. 4) mounted on the circuit substrate 7. As shown in FIG. 2, a plurality of external connection terminals (electrodes) 4 are formed on the terminal surface of the module 2. The external connection terminals 4 are formed by patterning a copper plate applied to the circuit substrate 7 by etching. It should be noted that the area indicated by double dashed chain lines in the center of each of the external connection terminals 4 in FIG. 2 corresponds to an effective are of each of the external connection terminals 4.
As shown in FIG. 3, the IC chip 8 is mounted on the mounting surface of the module 2, and is encapsulated by seal resin. Antenna connection terminals 5 are formed on the mounting surface outside the seal resin 9.
FIG. 4 is a plan view of the module 2 before the IC chip 8 is encapsulated by the seal resin 9. The IC chip 8 is mounted on the center of the circuit substrate 7. The electrodes of the IC chip 8 are connected to respective lead wires 10 formed on the mounting surface of the circuit substrate 7 by bonding wires 11, respectively. The lead wires 10 are electrically connected to the respective external connection terminals 4 on the terminal surface of the circuit substrate 7 via respective through holes 12.
A description will now be given, with reference to FIG. 5, of a process of incorporating the module 2 into the card body 1. The card body 1 is previously provided with antenna 3. A recess 1a is formed in a predetermined portion of the card body 1. Opposite ends of the antenna 3 are exposed in the vicinity of the recess 1a so that the antenna connection terminals of the module 2 are connected thereto.
First, paste-like solder 13 is applied onto the antenna connection terminals 5 of the module 2. Then, the module 2 is assembled to the card body 1 so that the seal resin 9 fits in the recess 1a of the card body 1. At this time, the solder 13 on the antenna connection terminals 5 contacts the opposite ends.of the antenna 3. In this state, a heating jig (solder iron) is pressed from the terminal surface side of the module 2 so as to melt the solder 13 by heat from the heating jig o connect the antenna connection terminals 5 and the ends of the antenna 3 to each other. The heating jig is configured and arranged to locally heat a portion corresponding to the antenna connection terminals 5 so that the heat provided by the heating jig is not transmitted to the IC chip 8 as much as possible. Additionally, since the card body 1 is formed of a plastic material having a relatively low heat resistance, the heating temperature must be controlled so that the temperature of the solder 13 does not exceed the melting point of the solder too much.
FIG. 6 is a side view of the module 2 for explaining the process of incorporating the module 2 into a sheet provided with antenna. In the case of FIG. 6, the antenna 3 is applied to the sheet 14. The sheet 14 is provided with an opening 14a in which the seal resin 9 of the module 2 is fitted. The heating jig shown in FIG. 6 is also configured and arranged to locally heat a portion corresponding to the antenna connection terminals 5. Additionally, since the sheet 14 is formed of a material having a relatively low heat resistance, the heating temperature must be controlled so that the temperature of the solder 13 does not exceed the melting point of the solder too much.
However, in order to melt the solder 13 applied to the antenna connection terminals 5 provided on the mounting surface by heating from the terminal surface, side, there may be following problems.
1) In order to melt the solder 13 by making the heating jig in contact with the external connection terminals 4, the heat must be transmitted through the circuit substrate 7. However, the circuit substrate 7 is formed of a material, which has a relatively low thermal conductivity. Accordingly, in order to melt the solder 13, the temperature of the heating jig must be raised or the heating time must be increased.
2) The external connection terminals 4 are formed of copper, which has a high thermal conductivity. Accordingly, the heat of the heating jig can easily transmit to a portion adjacent to the IC chip 8, which results in heating of the IC chip 8 by the heat from the hating jig. The temperature rise in the IC chip 8 affect the reliability of the IC chip.
3) Since the soldering process is performed in a state in which the module 2 is assembled to the card body 1 or incorporated into the sheet provided with antenna, portions to be soldered by the solder 13 are covered by the circuit substrate 7. Thus, the state of soldering cannot be checked by visual inspection.
4) If the amount of the solder 13 is in excess, the melted solder may spread to the lead wires 10 and the through holes 12 located in the vicinity of the antenna connection terminals 5, resulting in short circuiting the antenna connection terminals 5.
5) Since the area of the soldered portion is small, the strength of the soldered portion may not be sufficient.
It is a general object of the present invention to provide an improved and useful combination card in which the above-mentioned problems are eliminated.
A more specific object of the present invention is to provide a module of a combination card, which module can be incorporated into a card body with solder being easily melted and heat transmission to portions other than the antenna connection terminals being reduced.
In order to achieve the above-mentioned objects, there is provided according to one aspect of the present invention a combination card comprising: a card body provided with an antenna; and a module including a substrate which has a terminal surface on which at least one external connection terminal is formed and a mounting surface opposite to the terminal surface, an IC chip being mounted on the mounting surface, wherein said module includes at least one antenna connection terminal located on the mounting surface, the antenna connection terminal being connected to the antenna, and at least a part of the antenna connection terminal is exposed on the terminal surface.
According to the above-mentioned invention, when the module is assembled to the card body, the antenna connection terminal is connected to the antenna by a solder (or a silver paste). That is, the soldering is performed by melting the solder applied to the antenna connection terminal exposed on the mounting surface by pressing a heating jig against the antenna connection terminal exposed on the terminal surface. Accordingly, if the antenna connection terminal has a part exposed on the terminal surface, heat can be transmitted from the heating jig to the solder by passing through only the antenna connection terminal by pressing the heating jig against the exposed part of the antenna connection terminal. Thus, the solder is efficiently heated, and the temperature of the heating jig and the heating time van be reduced. Therefore, the card body and the IC chip mounted on the mounting surface can be prevented from being influenced by the heat from the heating jig.
In the combination card according to the present invention, the antenna connection terminal may be separated from the external connection terminal. In such a structure, the heating jig can be made in contact with only the antenna connection terminal formed on the mounting surface of the module. Since the antenna connection terminal is separated from the external connection terminal formed on the terminal surface, the heat supplied to the antenna connection terminal does not transmit to the external connection terminal via a metal part. Accordingly, the heat from the heating jig does not transmit to other parts such as the IC chip on the substrate via the external connection terminal.
Additionally, in the combination card according to the present invention, the antenna connection terminal may include a first antenna connection terminal formed on the terminal surface and a second antenna connection terminal formed on the mounting surface, and the first antenna connection terminal is electrically connected to the second antenna connection terminal via a through hole having a metal plated inner surface.
Accordingly, when the antenna connection terminal is heated by the heating jig, heat transmitted from the heating jig to the first antenna connection terminal reaches the second antenna connection terminal by transmitting the metal plated portion of the inner surface of the through hole. That is, the heat from the heating jig reaches the solder by transmitting a metal part. On the other hand, in the conventional module, the heat from the heating jig transmits from the antenna connection terminal to the solder via the substrate. Thus, according to the present invention, the heat from the heating jig transmits to the solder faster and more efficiently than the conventional module. Accordingly, the temperature of the heating jig can be set lower than that of the conventional module, and the heating time can be reduced. As a result, an amount of heat transmitted to portions other than the solder can be reduced, which prevents the card body from being deformed due to the heat. Additionally, since the amount of heat transmitted from the heating jig to the IC chip is reduced when the heating time is short, the temperature rise of the IC chip can also be reduced.
Additionally, a state of soldered portion can be checked by observing inside of the through hole after the soldering process is completed. Thus, a reliable soldering can be performed. Further, if the amount of solder is in excess, the excessive solder does not spread around the antenna connection terminal and is filled in the through hole. Accordingly, thee antenna connection terminal is prevented from short-circuiting due to the excessive solder. Additionally, even if an appropriate amount of the solder is: applied to the antenna connection terminal, some amount of the melted solder is filled in the through hole. Thereby, the soldered area is increased, and eth strength of soldered portion is increased.
Alternatively, in the combination card according to the present invention, the antenna connection terminal may be formed on the mounting surface, and at least one conductive bonding member may extend between the terminal surface and the mounting surface by passing through the substrate of the module so as to connect the antenna connection terminal to the antenna.
Additionally, there is provided according to another aspect of the present invention an IC card module configured and arranged to be used in a combination card, the IC card module comprising: a substrate having a terminal surface on which at least one external connection terminal is formed and a mounting surface opposite to the terminal surface; an IC chip mounted on the mounting surface; and at least one antenna connection terminal connected to an antenna provided in the combination card, at least a part of the antenna connection terminal being exposed on the terminal surface of the substrate.
Further, there is provided according to another aspect of the present invention a manufacturing method of a combination card provided with an IC card module incorporated into a flat member provided with an antenna, the manufacturing method comprising the steps of: applying an electrically conductive bonding material onto at least one antenna connection terminal provided in the IC card module; placing the IC card module in a predetermined position on the flat member; and bonding the antenna connection terminal to the antenna by the electrically conductive bonding material by heating said antenna connection terminal exposed on the terminal surface of said IC card module.
Other objects, features and advantages of the present invention will become more apparent from the following detailed description when read in conjunction with the accompanying drawings.